21245722416 has 80 divisors (see below), whose sum is σ = 61066091520. Its totient is φ = 7072269120.

The previous prime is 21245722367. The next prime is 21245722429. The reversal of 21245722416 is 61422754212.

21245722416 is a `hidden beast` number, since 21 + 24 + 572 + 2 + 41 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 287881 + ... + 354071.

It is an arithmetic number, because the mean of its divisors is an integer number (763326144).

Almost surely, 2^21245722416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21245722416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30533045760).

21245722416 is an abundant number, since it is smaller than the sum of its proper divisors (39820369104).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21245722416 is a wasteful number, since it uses less digits than its factorization.

21245722416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66951 (or 66939 counting only the distinct ones).

The product of its digits is 53760, while the sum is 36.

The spelling of 21245722416 in words is "twenty-one billion, two hundred forty-five million, seven hundred twenty-two thousand, four hundred sixteen".